The transit system has compressed natural gas, clean diesel and hybrid buses. Metro's board was expected to approve a $200,000 study Thursday by West Virginia University Research Corp. to perform emissions testing and collect data on vehicle performance and operating costs.

The initial study will be funded by the East Coast Hybrid Consortium, a coalition that promotes alternative fuel technologies. Metro said the goal is to determine which bus system will be preferred for future purchases. The agency has been working to buy 100 or more new buses each year, as funds are available.